[PATCH 16/22] arm64: dts: qcom: msm8998: Reserve low IOVA range for Venus

Venus VPU reserves IOVA addresses below 0x25800000 (600MB), primarily for
secure non-pixel buffers. DMA into that range, from any other stream id
would triggers unhandled SMMU page faults that cause spontaneous device
reboots. This is readily reproduced with one or more browser tabs
driving multiple concurrent video decode streams.

Add a reserved-memory IOVA reservation node covering [0, 0x25800000]
and reference it from the venus node so the IOMMU layer keeps DMA
allocations above that boundary.

Fixes: 1c6285e10d76 ("arm64: dts: qcom: msm8998: add venus node")
Cc: [email protected]
Signed-off-by: Vikash Garodia <[email protected]>
---
 arch/arm64/boot/dts/qcom/msm8998.dtsi | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/boot/dts/qcom/msm8998.dtsi b/arch/arm64/boot/dts/qcom/msm8998.dtsi
index 5038d0009c1a90851af1de91925facb4117d82fc..08a9e80ad6e1a17db1ced3a1ffc0c28bb35e84ad 100644
--- a/arch/arm64/boot/dts/qcom/msm8998.dtsi
+++ b/arch/arm64/boot/dts/qcom/msm8998.dtsi
@@ -116,6 +116,17 @@ mdata_mem: mpss-metadata {
 			size = <0x0 0x4000>;
 			no-map;
 		};
+
+		/*
+		 * The Venus VPU reserves IOVA below 0x25800000 (600MB),
+		 * primarily for non-pixel buffers using different Stream IDs.
+		 * DMA into that range triggers unhandled SMMU faults and
+		 * spontaneous reboots, so reserve it to keep IOMMU
+		 * allocations above this boundary.
+		 */
+		venus_iova: venus-iova {
+			iommu-addresses = <&venus 0x0 0x25800000>;
+		};
 	};
 
 	clocks {
@@ -3201,7 +3212,7 @@ venus: video-codec@cc00000 {
 				 <&mmss_smmu 0x42d>,
 				 <&mmss_smmu 0x411>,
 				 <&mmss_smmu 0x431>;
-			memory-region = <&venus_mem>;
+			memory-region = <&venus_mem>, <&venus_iova>;
 			status = "disabled";
 
 			video-decoder {

-- 
2.34.1